A circulation-type fuel cell system in which an ejector is provided in a supply passage for supplying anode gas to a fuel cell and excess anode gas not consumed by the fuel cell is sucked by the ejector and supplied to the fuel cell is known as one of fuel cell systems.
JP2008-190336A discloses a technique for controlling an injection timing of an injector provided upstream of an ejector so that a supply flow rate obtained by adding an injection flow rate from the injector and a suction flow rate by the ejector becomes a flow rate satisfying power required from a load.